1. Field of the Invention
The invention relates to an audio device. Particularly, the invention relates to a speaker.
2. Description of Related Art
Two most direct sensory responses of mankind are visual system and hearing system. Therefore, scientists have been dedicated to develop devices or system techniques related to the visual system and the hearing system. Presently, electroacoustic speakers are mainly classified into direct and indirect radiation speakers, and according to driving methods thereof, the speakers are mainly classified into moving-coil, piezoelectric and electrostatic speakers. Whatever the speaker is, main components thereof include an electrode layer, a diaphragm and chambers.
In detail, the diaphragm includes an electret layer, and after a charging process, the electret layer may have a charge-maintaining effect in internal of the material. The electrode layer is adapted to receive sound source signals to attract or repulse charges of the electret layer, so as to drive the diaphragm to produce sounds. According to a current design, a single electrode layer is generally used to receive the sound source signals to drive the diaphragm to vibrate, and the sound output thereof is monotonous and lack of variety.